1. Field of the Invention
The subject of the invention is a railroad wheel with a wear resistant flange used in the different kinds of rail transport: railways, trams and mine transport.
2. Background Art
In railway engineering serious problems occur with excessive grinding of the lateral surfaces of flanges of wheel rims. The smallest offset of wheel sets in a rail track results in rolling of wheels along circles having different radii and in consequence results in a change of the angle of attack of a wheel onto the rails. During rolling of axle sets on a straight track, the wheel flanges in principle do not touch the rails at definite speeds, but on curves at high speeds considerable friction results between these flanges and a head of the rail, which results in high grinding and thus to wear, also called undercutting of these flanges (sharp flanges), which could even threaten travelling safety in railway transport.
The steady quiet running of the rail-vehicle, the travelling safety, and the noise level emitted while a vehicle is travelling on the track, as well as the interval of time between subsequent very expensive repairs of the wheel sets depends in large measure on the geometrical features of the rolling profile. Within the framework of these repairs to the wheel sets, the railroad wheels are re-profiled in order to restore the correct dimensions of the wheel sets.
Up to now, for example, in order to reduce the grinding of the wheel flanges and to prolong the overhaul intervals, different kinds of lubricants and devices for lubrication of the above mentioned wheel flanges and rails have been used, particularly on the curves in the track.
From the analytical & theoretical publication, “Application of elastohydrodynamic theories of lubrication to rail/wheel systems with curved tracks”, Technical University of Silesia—fascicle 22 (transport), M. Sitarz, H. P. Evans—1994, the elastohydrodynamic lubrication of railroad wheel flanges is known during travelling on curves in a track with high external loads. It is foreseen, that such lubrication of the wheel-rail system can reduce the wear of rails and wheels 5-7 times and reduce the fuel consumption by about 30%. Such foreseen results of reduced wear and fuel consumption are based on numerical calculations that the biggest changes in oil film thickness occur within the radius range R=(13-15) mm.
The publication, “Running gears of track-vehicles”, Z. Romaniszyn, Ed. Technical University of Krakow, 2005, discloses known devices for lubrication of wheel flanges using oils, sticky greases or solid oils. The latter comprise inserts manufactured from polymer-stabilized constituents, enabling obtainment of low friction factor values, ranging from 0.06 to 0.1, which are insensitive to variations within a wide temperature range. The known lubricant application devices also include, among other things, an appliance consisting mostly of an electronic control system, connected with a transmitter of a speedometer, a feeding conduit, an oil tank, a pneumatic solenoid valve, a spraying device and low-pressure oil and air pipes. The primary task of the electronic control system is controlling the pneumatic and hydraulic part of the lubrication system, which lubricates the borders of rail and wheel surfaces. The operating personnel of a track-vehicle chooses the track sections requiring activation or stoppage of the above mentioned lubricating system.
The hitherto existing methods and devices aiming at increasing the durability of railroad wheels by lubricating the flanges of the latter are difficult and troublesome ones. The common disadvantage of these solutions is imperfect devices and control systems to determine the dosage of lubricant. The lubrication of the wheel flange should be performed at a close distance to the beginning of the curve in the track in an exactly determined place, that is on the wheel flange. An inaccurate supply of lubricant will not fulfill the required task, and, in addition, the grease could flow onto the rolling surfaces of the railroad wheels producing disturbances in vehicle braking.